Method of making producer gas



Jan. 24, 1928.

W. M. CROSS METHOD OF MAKING PRODUCER GAS Filed April 28, 1927 mw Tmw y xvA WW www Patented dan. 214,y 1928.

UNITED STATES WALTER M. CROSS, OF KANSAS CITY, MISSOURI.

METHOD OF MAKING PRODUCER GAS.

Application led Apr128, 1927. Serial No. 187,198.

This invention relates ,to improvements in gas producers and refers more particularly to a system in which gas of a relatively higher B. t. u. content is produced than that o manufactured at the present time in gas producers utilizing either oil or coal as the charging medium.

This application is a continuation in part of a copending application. Serial No. 151,- 420, filed November 29, 1926.

Among the objects of the invention are to provide a gas producer which is not subject to colring or clinlrering, free from shutdoivns or low gas production periods, to provide a gas producer in which gas is made having a. relatively high and uniform heat unit content, and to provide a gas producer relatively cheap to operate because of the economical use of the exhaust steam, and

2G waste heat 'from the gas made in the producer.

The system provides furthermore for the creation and maintenance of predetermined temperatures controlled at substantially the reaction temperature of the formation of carbon monoxide and hydrogen from coal and steam; to provide a coal dust gas producer which gives the contents great turbulence While the materials are undergoing reaction, and in general to provide a system hereinafter described in more det-ail.

Fig. 1 is a diagrammatic side elevational View of the gas producing system.

Fig-2 is a view taken along the line 2--2 in Fig. 1. -r

Referring to the drawings, at 1 is shown a` coal hopper or bin, which communicates through a conduit 2 with a funnel like feed hopper 3, Which is mounted upon the pulverizer 4. The pulverizer is driven by meansof a motor diagrammatically shown at 5, or by any other suitable available source of power. The discharge from the pulverizer is delivered into the bin 6 and a screw conveyor 7 driven by a shaft 8 upon which a pulleyi) is mounted. The pulley 9 upon the shaft is driven from any suitable source of power, (not shown) operating at a uniform rate. 'The pulverized material,

which is fed by the screw conveyor passes into the annular duct 10,surrounding the gas producer near its top. VV To this annular space, or duct is also fed preheatedr air and superheated steam through the pipe or conduit 11.

The superheated steam is supplied by the through a series of banks of coils designated as 19 and 20 in the air and steam superheater 21.

The air and steam superheater is fired either by gas, oil or coal, the combustion gases passing from the chamber 21a over the baille Wall 22 and downwardly through the chamber in which the coil 19 is positioned. 1n the drawings an oil burner is diagrammatically shown at` 21". spent combustion gases are directed thence through a flue 23 and into the heat exchanger 24, where they are brought in heat exchange relation with cool air introduced through the pipe 25. After being cooledby the heat transfer in the exchanger 24 the combustion gases pass oi to a flue 26.

The air, as suggested, introduced through the pipe 25 receives heat from the combustion gases in the exchanger 24 and passes through the line 26d to an air pump 27 driven bv a motor 28. A portion of the pre- 'zel These partially heated air passing through the line 26d may be diverted therefrom through pipe 26%, and supplied to the burner 21b utilized to heat' the air and steam super-heater. Thus,

4an accurate regulation of the preheated air is possible as a supply to the air and steam mixture in the gas making process and also an efieient utilization ofthe heat contained in gases in the flue 23 is effected. By means of the pump 27 the air is discharged through the second heat exchanger 15 in which it is combined With the steam introduced thereto through the line 14. In the exchanger 15 the preheated air and steam receives additional heat from the highly heated gas discharge from the producer through the line 17. The combined air and steam ass through the line 18 and receive their nal line 96d and QG in the line 26" tarnish means for controlling the amount of preheated air combined with the. steam and the portion diverted to thc burner.

Returning to the construction of the gas producer' and the method of manufacturing gas from the fuel supplied through the screw conveyor and conduit 10 and the preheated air and superheated steam supplied through the line 11, these materials are introduced to the producer through tuyres or injection noz/.les 35, which are set at an angle in order that the materials will he injected substantially tangentially into the. circular producer. The producer is highly insulated to prevent in .so far as is possible a loss of heat by radiation. The mixture 0r charge, as suggested, is given a whirling or `spiral motion on its injection into the producer and continues this whirling turbulence throughout its travel from the top of the producer to the bottom where the gas passes out through a baille discharge line 17; the hood 36 separating impurities and dust from the gas. The producer is equipped with a cleanout hole 3T which is covered by a re- 'movable plate 38. In the bottom of the producer is a liquid slag or residue draw-olf pipe 39, controlled by a valve 40.

The producer gas discharged through the line 17 passes through the heat exchanger 15 where it gives up a considerable part of its heat to the steam and air introduced through the pipes 14 and 34 respectively. From the exchanger the gas passes through the pipe 41 into the dust separator 42, the marketable gas being delivered through a line 43 to a gas holder 44 from which it may be drawn and disturbed by the pump 12, which has a suction line 45 communicating with the gas holder and a discharge line 46 for delivery of the gas to the mains or other desired delivery point.

In the system it is contemplated to heat the air and steam to a temperature of reaction by passing it through the stack or flue of the superheater and gas cooler in series. By raising the mixture ofl air and steam to, or above, this reaction temperature, it is unnecessary otherwise to rely upon a partial combustion of air in the producer to maintain the heat of reaction and thereby reduce the quality of the gas made.

The maintenance of the predetermined temperature of reaction of the air and steam mixture may be e'ccted by an automatic control diagrammatically shown at 48. This control is operated by a pyrometer 49, interposed in the line 11 operating a valve, 48, which regulates the fuel supply to the burner 21b by which the air and steam superheater is fired.

The introduction of the air and steam mixture with the pulverized coal or oil partieles is made to promote a high degree of turbulence in the reacting stage or producer, and While operating` effects not only an intimate combination of the constituents, but improves the character of the. gas produced. The process is continuous. as contrasted with the normal type of gas producer operation. in which a considerable period of the operation is taken up with the heating of the producer to the desired reaction temperature. or the temperature at which the air and steam will combine with the pulverized fuel or oil constituents to produce the quality of gas desired.

The producer is free from the difficulties incidental to eoking and channeling eommon to most gas producers. The cokina and channeling materially slows down the production of the producer and seriously affeets its eliiciency.

In the present assembly or construction there is provided a means for superheating steam and air mixtures to a predetermined temperature more or less according to thc number of B. t. n.s required in the gas. Thus. when a gas is desired having a high B. t. u. content. a very small amount of air and relatively large amount of steam. heated to a temperature say in the neighborhood of 220Go F., is used for introduction to the producer to be combined with the coal dust. Temperatures will vary according to the. character of the fuel used. Due to the fact that so much heat is brought in by means of the air and steam mixture, there will be. relatively little combustion required to keep the temperature of the gas producer at a proper reaction temperature for the economical production of the producer gas.

Under the above conditions the dilution by nitrogen of the atmosphere is greatly minimized and accordingly the gas'has a correspondingly higher heating value per cubic foot.

AWhen transportation distances are relatively short, and it is not desired to produce a gas having such high B. t. u. value, the steam is superheated to a lesser degree.

In the present construction means are provided for pulverizing the coal and for blowing it or transferring it into the gas producer by means of superheated steam and air. The steam, preferably that taken from a pump` such as a gas distributing pump, 1s superheated by being brought in heat exrecovery shown in the present custom will ellect a saving so that the actual cost ot heating the air and steam is greatly minimized over what has been the general practice heretofore.

` Briefly, then, the novelty in the present invention lies primarily (l) In the making of producer gas from carbonaceous material, preferably in a finely divided condition. This carbonacemis ma- .terial may Aconsist of a coal ,peat, coal dust,

or heavy oil having a. relatively high carbon content.

(2) The systcm'atl'ords a process tor producing a gas of relatively high B. t.u. content by superheating the steam and air required ;tor the production oi. producer gas. to a predetermined temperature of reaction.

(3) In the combination and utilization ot' Y the exhaust steam from pumps and the heat exchanging equipment by means otl which the heat of the gas discharged from the producer is transferred to the air and steam being introduced thereto: also the use o't' supplementary superheater for the air and steam in combination with a heat exchanger in the iiue of the superheater for taking advantage of the heat of the lue gases.

(4) In a means for withdrawing the slag while the gas producer is operating and for burning the fuel advantageously.

(5) In a process in which the steam and air are heated substantially to or above the reacting temperature. A condition which promotes the rapidity of gas production during which reaction the carbonaceous material combines with the steam and air to form carbon monoxide and hydrogen in a desired and controlled amount.

(6) In the. placing of the inlet for the carbonaceous material and steam in a position on the producer so that the mixture is projected into the producer approximately tangentially to the inner surface of the cylindrical wall of the producer, thus giving greater turbulence to the constituents undergoing reaction, which promotes a more complete combination.

I claim as my invention:

1. A method of making producer gas, comprising the steps ot' charging pulver-ized carbonaceous material to a stage of reaction, with mixed air and steam, said air and steam being heated to or above'a predetermined temperature ot' reaction whereby producer gas results, and automatically controlling the temperature of the air and steam mixture.

2. A method ot' making producer gas, comprisingl the steps of charging pulverlzed carhonaceous material to a stage of reaction, with mixed air and steam, said air and steam being heated to or above a predetermined temperature ot' reaction whereby producer gas results, and automatically regulating the air and steam mixture to the predetermined temperature of reaction.

WALTER M. CROSS. 

